Bifurcated stent grafts are well known for treating abdominal aortic aneurysms. Such stent grafts typically include a tubular body which extends in the aorta towards the renal arteries of a patient and a bifurcation. The bifurcation usually has a shorter leg and a longer leg. Once the bifurcated graft is deployed, an extension leg is provided to extend down one iliac artery from the shorter leg, with the longer leg extending down the other iliac artery.
There can be problems with such stent grafts, however, for example in cases in which the iliac artery is extremely convoluted, as is often the case with older patients. The extension leg provided to extend down one iliac artery from the shorter leg of the bifurcated aortic stent graft can be kinked in the convoluted region, thereby blocking off blood flow to the iliac and femoral arteries. In some instances the iliac artery can kink immediately beyond the end of the extension leg, again causing blood flow restriction.
WO 03/053286 describes an endovascular prosthesis including a first end, a furcated second end, and an anchoring means. The first end has a longitudinally extending central lumen and means for laterally supporting the first end. The furcated second end includes at least two branches that extend from an intersection of the furcated second end. Each of the branches includes a longitudinal support means and a branch lumen in fluid communication with the central lumen of the first end. The anchoring means secures the first end within a vasculature.